ILLUSTRATIONS. VII 



27, A. Branches of Acacia siiblanata, showing small and rigid phyllodia, Quorn. 



B. Eutaxia empetrifolia, showing the small flowers and linear short leaves, Quorn. 

 c. Branches of Acacia pycnantha, the "golden wattle," showing the character of the 

 large phyllodia, Quorn. 



28, A. View about 2 miles west of Quorn, taken from a grassy ridge and looking upon a ridge 



which is covered with mallee. In the intervening valley are a few specimens 



of EwxHyptus leucoxylon var. pauperita. 

 B. Hakea leucoptera on the edge of the mallee scrub, about 2 miles north of Quorn. 



Small shoots which spring from superficial roots of the larger plants are in the 



foreground, 

 c. Western slope of ridge along Mount Arden road, Quorn, with Triodia irritans and 



Trichinium, dominant grasses. Dead fruiting stalks of Xanthorrhcea semi- 



plana shown in the foiiegroimd; mallee. Eucalyptus sp., in the background. 



29, A. Boasicea walkeri on sunimit of a sandhill by Station 40S, near Ooldea. 



B. Hakea mvUilinecUa on the crest of a sandhill by Station 408, near Ooldea, with Euca- 

 lyptus incrassata var. dumosa, a mallee, in the flats below. Bunches of 

 spinifex, Triodia irritans, are to be seen between the mallee. 



c. Branch with withered flower-spike and leaves of Hakea multilineata, from Station 

 408, near Ooldea. 



D. Mdaleu^M uncinata in fruit, from the sandhills by Station 408, near Ooldea. 



30, A. A community of Acacia pycnantha, the golden wattle, by a streamway on the Mount 



Brown road, Quorn. 

 B. A large specimen of Eucalyptus leucoxylon var. pauperita, by a wash on the Mount 



Arden road, Quorn. A comparison with the automobile will give an idea of 



its size. 

 c. Vegetative reproduction in Hakea leucoptera. A young shoot, removed from the 



soil, is shown taking its origin from a horizontal root. Quorn. 



31, A. Exposure of roots of mallee, Eucalyptus sp., by a narrow wash, showing the abun- 



dance of superficial roots. Along the Mount Arden road, Quorn. 

 B. Root exposure of Eucalyptus leucoxylon var. pauperita by erosion of the bank of 

 stream above Warren's Gorge. The roots were washed out for a distance 

 exceeding 16 meters. Quorn. 



32, A. Scattered groups of Melaleuca parviflora, in the mallee scrub near Blanchtown. 



B. Flood plain of the Murray River showing open forest of Eucalyptus rostrata partly 



submerged, Blanchtown. 

 c. View in mallee. Eucalyptus sp., scrub on Murray flats near Blanchtown. 



FIGURES. 



1. Physical divisions of Australia, after Gregory, 1916, to which has been added the 



10-inch isohyet. The shaded areas have an altitude of 1,000 feet or more 

 above the sea. 



2. Mean annual rainfall map of Australia, adapted from Himt. 



3a. Duration of wet seasons, after Taylor, 1916. "The periods shown on the map include 

 those months in which the average rainfall exceeds the geometric mean of the 

 monthly rainfalls." 



3b. Wettest months of the year, after Hunt's meteorological map of Australia, 1916. 



4a. Mean rainfall of Austrsdia for January, after Hunt. 



4b. Mean rainfall of AustraUa for April, after Hunt. 



5a. Mean rainfall of Australia for July, after Hunt. 



5b. Mean rainfall of Australia for October, after Himt. 



6. Graphs, after Hunt, showing average monthly rainfall and mean monthly evaporation, 

 in inches, for various places in AustraUa. 



7a. Mean humditiy of Australia for January, after Taylor, 1918. 



7b. Mean humidity of AustraUa for July, after Taylor, 1918. 



8a. Mean annual evaporation in Australia, after Hunt. 



8b. Average yearly temperature of Australia, after Hunt. 



9a. Mean temperature of AustraUa for January, after Hunt. 



9b. Mean temperatmre of AustraUa for July, after Hunt. 



